package Crypt::OpenPGP::ErrorHandler;
use strict;
use vars qw( $ERROR );
sub new { bless {}, shift }
sub error {
my $msg = $_[1];
$msg .= "\n" unless $msg =~ /\n$/;
if (ref($_[0])) {
$_[0]->{_errstr} = $msg;
} else {
$ERROR = $msg;
}
return;
}
sub errstr { ref($_[0]) ? $_[0]->{_errstr} : $ERROR }
1;
__END__
=head1 NAME
Crypt::OpenPGP::ErrorHandler - Crypt::OpenPGP error handling
=head1 SYNOPSIS
package Foo;
use Crypt::OpenPGP::ErrorHandler;
use base qw( Crypt::OpenPGP::ErrorHandler );
sub class_method {
my $class = shift;
# Stuff happens...
return $class->error("Help!");
}
sub object_method {
my $obj = shift;
# Stuff happens...
return $obj->error("I am no more");
}
package main;
Foo->class_method or die Foo->errstr;
my $foo = Foo->new;
$foo->object_method or die $foo->errstr;
=head1 DESCRIPTION
I<Crypt::OpenPGP::ErrorHandler> provides an error-handling mechanism
for all I<Crypt::OpenPGP> modules/classes. It is meant to be used as
a base class for classes that wish to use its error-handling methods:
derived classes use its two methods, I<error> and I<errstr>, to
communicate error messages back to the calling program.
On failure (for whatever reason), a subclass should call I<error>
and return to the caller; I<error> itself sets the error message
internally, then returns C<undef>. This has the effect of the method
that failed returning C<undef> to the caller. The caller should
check for errors by checking for a return value of C<undef>, and
in this case should call I<errstr> to get the value of the error
message. Note that calling I<errstr> when an error has not occurred
is undefined behavior and will I<rarely> do what you want.
As demonstrated in the I<SYNOPSIS> (above), I<error> and I<errstr> work
both as class methods and as object methods.
=head1 USAGE
=head2 Class->error($message)
=head2 $object->error($message)
Sets the error message for either the class I<Class> or the object
I<$object> to the message I<$message>. Returns C<undef>.
=head2 Class->errstr
=head2 $object->errstr
Accesses the last error message set in the class I<Class> or the
object I<$object>, respectively, and returns that error message.
=head1 AUTHOR & COPYRIGHTS
Please see the Crypt::OpenPGP manpage for author, copyright, and
license information.
=cut